Problem: Simplify the following expression: $11\sqrt{45}$.
Solution: First, try to factor a perfect square out of the radical. $= 11\sqrt{45}$ $= 11\sqrt{9 \cdot 5}$ Separate the radical and simplify. $= 11\sqrt{9} \cdot \sqrt{5}$ $= 11 \cdot 3 \cdot \sqrt{5}$ $= 33\sqrt{5}$